#include <stdio.h>

int main(){
    int x; /* a nomal interger*/
    int *p; /* a pointer to an interger(*p is an interger, p is
	       a pointer to an interger)*/

    p = &x; /* & used for get an value's address, so &x gets
    		the address of x .
		
		assigin the address to p*/
    scanf("%d", &x); /* "scanf" receice an value and store it
   			so it should know whitch address to store it.
			it needs an address. &x means the address whrere
			store x's value*/
    printf("%d\n", *p); /* "printf" output some values*, so it
			   need to get those value. *p means the value
			   p points to*/
    getchar();
}
